Articulated Locomotives (HO Virginian 2-8-8-2)

fitz Jun 10, 2001

  1. 7600EM_1

    7600EM_1 Permanently dispatched

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    BNSF,
    Great picture man! That looks to be a UP Challenger???? I can't make out the number so I took a guess.... HA! :D
     
  2. watash

    watash Passed away March 7, 2010 TrainBoard Supporter In Memoriam

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    Looks like he's listing to port there, man is he haulin' the mail or what!
     
  3. bnsf4354

    bnsf4354 TrainBoard Member

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    I would have been quite undsettled to see that thing listing to port like that come straight at me!

    My favorite artic is the Big Boy, but alot of talk has been made about my 2nd favorite (the Allegheny) being better than or equal to the Big Boy. So I did some checking and discovered that the Allegheny was better in only two less important categories----weight on drivers and horsepower. The Big Boy had over 25,000lbs more tractive effort. It also had virtually no wheel slip tendencies. Perhaps what I was more surprised to find was that the NW Class A had more tractive effort than the Allegheny! In fact a challenger almost had as much TE as the Allegheny! I'll put the results below for camprisons:

    [RR] [Cab#] [Wheel/Driver] [Class] [Builder/yr] [Tractive Effort] [HP] [Top MPH]

    [N&W] [1238-42] [2-6-6-4.70] [A1] [1950 N&W] [126,000] [6,300] [70]
    [C&O] [1600-59] [2-6-6-6.67] [H-8] [1941-48 Lima] [110,200] [7,500@40] [70]
    [UP] [3930-49] [4-6-6-4.69] [4664-5] [1944 ALCO] [97,400] [70]
    [UP] [4020-24] [4-8-8-4.68] [4884-2] [1944 ALCO] [135,375] [6,280@37] [80]

    [ 22 July 2001: Message edited by: bnsf4354 ]</p>
     
  4. watash

    watash Passed away March 7, 2010 TrainBoard Supporter In Memoriam

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    As near as I can make out, that Challenger is #3935 which would make it one of the swing only type that had better traction and smoother ride than the older ones where the front set of drivers could also move up and down independant of the boiler. That curve is not elevated either!

    The largest diameter cylinders I have any record of, were on a series of compound mallets like the one below. You can see this old dude had slide valves on the front, and piston valves on the rear so is not the oldest type. This is a B&O #7324 made in 1923. I used this photo because it has the man standing close to the 44" diameter front cylinders for a comparison of size. I though there was a logging mallet that had larger cylinders, but it turned out to be narrow gauge and had 40" cylinders, so looked like the cylinders were super big. Can you emagine the force you could generate at 200 pounds per square inch behind those 44" cylinders? I really have my doubts about that guy holding that engine back if the engineer wants to move it! :D

    [​IMG]
     
  5. 7600EM_1

    7600EM_1 Permanently dispatched

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    Watash,
    That picture is of an EX. BR&P 2-8-8-2, which is the B&O's in the photo, hence the renumbering!!!!! Its an EE-2!!!!!!! :D I finally got orginal pictures of that to look at to see if I wanted to model it.. And sadly I did all that effort and they are waaaay different then most 2-8-8-2's made and i'm boycotting that attempt. I thought being I never seen any of those that I would have been close.. I was wrong....

    Anyway I turned to making my 2-8-8-2 that are Rivarossi into B&O EL-6's being that the B&O's EL-6's were originally 2-8-8-2's and they removed the trailing truck to 2-8-8-0's, but they did run them as 2-8-8-2's and didn't like the trailing truck so, i'm going to model my 2-8-8-2 to an EL-6 before they amputated the trailing truck! :D

    I'm also going to make a "Triplex" from my old TYCO junk 0-8-0's and 2-8-0's. This project is still in the designing process so.... It is very possible hit or miss still or may not even get started i'm still thinking the process through and to make sure it is reasonable to do and reliable!!! I want to have power in it doing it so... that means the front 2 sets of drivers will be powered where the set back under the tender will be dummy and just follow the front set and look good. This is why a set of "Modelers liecence" are nice to have and use quite offen! HA! :D

    [ 22 July 2001: Message edited by: 7600EM_1 ]</p>
     
  6. 7600EM_1

    7600EM_1 Permanently dispatched

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    BNSF,
    Thiers a few things that come into play with your listing of the differences between loco's..... Always remember that the Big Boys and the Challengers were built for high speed travel.. (High Speed Freight Service).... Where as the Allegheny was made for lugging freight as low speeds thats why thr horse power on the Big Boys where @ 70 MPH and so on and the Allegheny's HP was at 40 MPH..... A big difference and alot of different things come into play here... All those loco's were made for a different purpose..... Thats why the HP TE are different and just because of that they had irregularly different purposes for the different Railroads that owned them!!! :D

    I will admit though the Challengers where the best tho out of them all... They had the power and the speed and where good for freight or passenger service. They were universal in use....
     
  7. watash

    watash Passed away March 7, 2010 TrainBoard Supporter In Memoriam

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    You beat me to it John, and you are correct, so I'll present a tool for instruction when learning about steam engines back in 1899. One of these would be a great conversation piece for the den or train room, wouldn't it?

    [​IMG]
     
  8. 7600EM_1

    7600EM_1 Permanently dispatched

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    Watash,
    Yes that WOULD be a nice piece in the den for a conversation piece.. I'd love that!!!! HA! :D That would be nice to have to start a decent conversation with another fellow model railroader, as it would almost have to be another STEAM FANATIC like myself....... :D
     
  9. bnsf4354

    bnsf4354 TrainBoard Member

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    EM1: I agree with what you are saying about the differences and am aware that each railroad used them differently. However, the numbers show that each of the locos produced their top HP in about the same speed range 30-45mph. I also realize that the higher HP allowed for easier sustained higher speeds, but again the Allegheny couldn't beat out the Big Boy. This may have had more to do with the better counter balancing on the Big Boy than anything else.

    What can be said for sure is that each railroad purchased the engine that most closely matched their needs. UP needed long fast freight power over sherman hill and through the long expanses of the west. C&O needed power for heavy freight and coal trains through winding territory, and N&W needed power for heavy troop and freight through rolling and twisting hills and valleys. Each got a unit suited well for its requirements.

    I will have to admit that the Challengers were probably the best overall----perhaps UP realized this as well since the Super Challengers were designed and built after the first Big Boys were delivered. Their versatility made them invaluable to the UP. More of them were made than any other simple artic on my list by a factor of at least 2!

    I am looking for more to post, but am running out of examples. [​IMG]
     
  10. watash

    watash Passed away March 7, 2010 TrainBoard Supporter In Memoriam

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    The railroad companies really took good care of you. They even posted adds like this on the bulletin board, just in case you wanted to save up for one. Even though this add came out in 1899, it still makes you stop and think.

    [​IMG]
     
  11. bnsf4354

    bnsf4354 TrainBoard Member

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    A few more. How about a doublehead shot of articulateds and a picture showing why a articulated was even created. Hope that thing stays on the track---wonder if it will make it around the curve?----YIKES!!
    [​IMG]
    [​IMG]

    [ 24 July 2001: Message edited by: bnsf4354 ]</p>
     
  12. fitz

    fitz Staff Member

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    Yeah, those UP 12-coupled monsters must have been a nightmare on curves. Does anyone know were any of the drivers "blind?" (no flanges). BNSF, where did you get that neat Challenger in your signature? :confused:
     
  13. watash

    watash Passed away March 7, 2010 TrainBoard Supporter In Memoriam

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    Alco's Brooks Works built the first 4-12-2 and delivered it in April 1926. Numbered 9000, it had three cylinders: the two outside cylinders were 27"x32" driving the third pair of drivers, and a centrally mounted cylinder 27"x31", driving the second pair of drivers. The first driver axle also had a crank on it to provide clearance for the main rod going to the second axle. Drivers were 67" diameter, and the fourth pair were blind (Flangeless) as a concession to curves that was found to be unnecessary due to the lateral-motion devices on the first and last pair of drivers. The lateral-motion devices were continued, but all subsequent models were fully flanged. This was the largest rigid wheel base engine in the World at the time. It road well at speed, and UP ordered 87 more like it. #'s 9000 to 9062 weighed 495,000 pounds, and #9063 to 9087 weighed 515,000. Roundhouse mechanics expected the Gresley valve gear to be a nightmare, but it was found that once correctly set and tuned, the valve gear lasted suprisingly longer than designed for, between maintainence shopping.

    There were some other 12-coupled engines build in other countries, but in 1934 Russia built an experimental 4-14-4 that looked like a monster. It only weighed 416,000 with 63" drivers. It was designed to only place 20 tons per axle on the light rail and frail roadbed available. When it made its demonstration run, it tore the track apart, and was stored, then later it was scrapped.
     
  14. 7600EM_1

    7600EM_1 Permanently dispatched

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    Guys,
    I tell ya the large wheel base loco's really get ahold of me I swear! :D Anyway.... Watash on that experimental 4-14-4, I read somewhere that it on its trial run on curves it would straighten out the curve!!!! Thats some wheel base!

    Anyway on the "Bald Face 9's" anyone have a diagram to the valve gear on them ??? I have this strange wanting to see how that actually worked and a few close up shots of the valve gear to acomadate the diagrams ???? I really like the way those engines looked for their size and all... But Articulated and Mallet types are sill my favorite rod loco's... Geared types... I must go with the Shays to be my favorite in that catagory........ :D Let me know if anyone has a diagram on the UP 9000's.... You all should have my e-mail address but if not here it is again anyway.. yellowstone10@hotmail.com

    [ 25 July 2001: Message edited by: 7600EM_1 ]</p>
     
  15. fitz

    fitz Staff Member

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    John, I have crawled all over the 9000 at the Pomona Fairgrounds and could kick myself for not getting some decent pix of the Gresley valve gear for the third cylinder. I can tell you that the crank on the second driver axle is humoungous. Might have some video of it, but the still pix don't show anything clearly.. There is another 3-cylinder engine there at Pomona, the SP 5021, a 4-10-2. Gresley valve gear is not new. A British invention, it has been around for a long time. Maybe Alan has some diagrams of the gear?? ;)
     
  16. bnsf4354

    bnsf4354 TrainBoard Member

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    I posted a picture of the Russian 14 wheeled driver either on this post or in the VGN post in HO forum. Truly huge.

    Just right click on the Challenger and look at the URL to find out where it came from. I found a BIG BOY like it, but couldn't get it to work for some reason---frustrating!
     
  17. bnsf4354

    bnsf4354 TrainBoard Member

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    I posted this photo on page 2 of this thread, but here it is for your viewing pleasure.
    [​IMG]
     
  18. watash

    watash Passed away March 7, 2010 TrainBoard Supporter In Memoriam

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    Another interesting insight into the Russian designer's mind: The piston rod was mounted on the 4th driver back from the cylinders, and required another connecting rod between the 4th and 5th driver to operate the valve gear. Inside next to each driver was a long hinged connecting rod connecting all 7 axles. American engines had the piston rod went to the 2nd driver, except for the 4-10-2 and the 4-12-2 that had the outside piston rods go to the 3rd driver. The American designers were attempting to reduce the reciprocating weight to lessen the pounding action on rails during high speed running. The weight of that long Russian piston rod was terriblely destructive to rails.
     
  19. fitz

    fitz Staff Member

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    I went back to the 1994 Pomona trip and didn't find any good Gresley pix, but like this one of Big Boy 4014 valve gear. Same year, shot the Big Boy 4005 at the OLD Forney Museum in Denver. Those were the first two Big Boys I had ever seen for real. You know, these engines are so big it is hard to get a decent photo of them when they are displayed. [​IMG] [​IMG] [​IMG]

    [ 26 July 2001: Message edited by: fitz ]</p>
     
  20. watash

    watash Passed away March 7, 2010 TrainBoard Supporter In Memoriam

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    Something that may not be clear to everyone, about what makes the 4-12-2 different than the "usual" American steam engines, is that Gresley valve gear.

    Two cylinder steam engines are driven by pushing or pulling on the crank pins on each drive wheel, like bicycle pedals. A bicycle pedal crank is 180 degrees opposed, so if one pedal is down and you stand on it, you can not move the bike no matter how much you push down on that pedal, or if you pull up on it. For that reason, steam engines were designed with one crank pin rotated 90 degrees ahead of the one on the other wheel so that when one crank ends up directly in line with the cylinder when stopped; the crank on the other wheel is able to push or pull the wheels off "center".

    One of the cylinders can either push or pull on the pair of wheels at any position anywhere around the circle. That is why you hear four exhaust chuffs for one revolution of the driver.

    (I know your smoking models only get one chuff per revolution, but that is not prototypical.)

    Think right and left, going foreward. Engine is at rest with left crank on dead center closer to the cylinder, crank on the right will be down. To move foreward: full steam pressure on the left piston will do nothing because it is trying to push directly in a straight line with the axle, so has no effect. But, steam pushing on the right piston can push the right crank back rotating the wheel to go foreward until the right crank reaches the dead center position away from the cylinder. While the rotation is going on, the left crank has been rotated down off center so that the left piston can now push against the left crank. This will then rotate the right crank up off center causing the valves to change so that steam now entering behind the piston on the right can pull the right crank foreward. Each time a crank reaches center (either close to the cylinder or farther away), the valves exhaust steam pressure (chuff) changing the pressure from pushing to pulling a piston. This happens four times every time the wheels turn one revolution.

    With a THREE cylinder engine, the cranks have to be set 120 degrees apart. The two outside cylinders work as does a two cylinder engine, only at 120 degrees around the circle from eachother, with the third cylinder working 120 degrees between the others. I is like a three bladed airplane propeller, see? So there will be 6 chuffs per revolution of a wheel. This complicates the valving, that I wont even try to explain here. Refer to my post above and see the central crank on the #2 axle below, and the casting that shows the two outer big holes for the cylinders, and the large hole in the center for the third cylinder. The smaller holes are for the valves. Note that the valve hole for the third cylinder id about 45 degrees above and to the left of the center cylinder. The front view of the engine shows part of the equalizing bars that operate the timing for all three sets of valves. This will give you an idea of the size of st pieces we worked on in the roundhouse. And you complain about your N scale pieces being too small to work with? Go work in the roundhouse! :D

    [​IMG]

    #2 wheel set with third cylinder crank

    [​IMG]

    The Gresley valve gear from the front

    [​IMG]

    Got that? :D

    [ 26 July 2001: Message edited by: watash ]</p>
     

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